package com.chongzi.cloud;

public class Singleton {
    private  volatile  static  Singleton instance =new Singleton();
    private  Singleton(){}

    public  static  Singleton getInstance(){
        if (instance==null){
            synchronized (Singleton.class){
                if (instance==null){
                    instance= new Singleton();
                }
            }
        }
        return instance;
    }
}
